Mechanism for latching shift key lever of typewriters



Oct. 7, 1958 o sT u 2,855,083

MECHANISM FOR LATC HING SHIFT KEY LEVER OF TYPEWRITERS File d June 24, 1955 ZiTORYS United States a n MECHANISM FOR LATGHIYG SHIFT KEY LEVER 0F TYPEWRITERS Henry L. Tholstrup, Rochester, N. Y., assignor, by mesne assignments, to the United States of America as represented by the Secretary of the Navy Application June 24, 1955, Serial No. 517,948 15 Claims. (Cl. 197-80) This invention relates to an improved case shift key lever and latch mechanism for typewriters and, more particularly, to a solenoid-actuated case shift key lever and latch mechanism.

In prior art mechanisms for latching the case shift key lever, such as shown in Figs. 19 to 21 of Patent 2,247,- 275, issued to A. H. Buckley, and Figs. 9 and 11 of my Patent 2,461,451 which discloses a solenoid-actuated case shift key lever and latch mechanism, it was the practice to place the shift button on the main key lever and to place the shift lock button on an auxiliary member which was rotatably fastened to the main key lever. This necessitated the employment of a retracting spring between the main key lever and the auxiliary member. When the shift lock member was to be solenoid actuated, additional separate linkages were also needed.

It is an object of this invention to provide a more simple case shift key lever latching mechanism.

It is a further object of this invention to provide a solenoid-actuated key lever latching mechanism which may be easily disassembled without making necessary any preliminary disassembly of the rest of the typewriter.

It is a more specific object of this invention to provide a solenoid actuated key lever latching mechanism which may be disassembled by merely removing a single screw.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

Fig. 1 is an exploded view of a key lever latching mechanism employing the principles of this invention, and

Fig. 2 is a cross-section of Fig. 1 along line 2-2.

Referring now to the figures, key lever 12 is pivotally mounted on the frame of the typewriter (not shown) at point 14 and key lever 16 is pivotally mounted on the frame of the typewriter at point 18. Member 20 located in a plane parallel to the length of key lever 12 is detachably mounted on key lever 12 by screw 22. Screw 22 includes a shoulder 24 about which member 20 is free to rotate. Proiection 26 overlaps key lever l2 and thereby prevents member 20 from rotating relative to key lever 12 in a clockwise direction. Depending from member 20 is a slotted portion 28 and a hooked portion 30. Hooked portion 36 cooperates in a manner to be discussed below with latch 32 which is secured to the typewriter frame.

Rigidly attached to key lever 12 on the other side thereof from hooked portion 30 is strip 34. Strip 34 has a hole in the lower end thereof. interposed between strip 34 and hooked portion 30 is strip 36. Strip 36 has pin 38 projecting at right angles therefrom, pin 38 being inserted into the hole of strip 34. The other end of strip Pin 44, which extends from element 46, is inserted in T 2,855,081 Patented Oct. 7, 1958 In operation, a force applied directly to key lever 12,

either by the actuation of solenoid armature 40 or by a shift lock button attached to strip 34, causes the free end of key lever 12 to be rotated in a clockwise direction about point 14. This causes a downward translational motion of member 20 at the point it is connected to key lever 12 by screw 22. However, due to the fact that pin 44 is inserted in the slot in slotted portion 28, slotted portion 28 of member 20 experiences no translational motion. Therefore, member 20 rotates in a counterclockwise direction about screw 22 and hooked portion 39 is moved down and forward. Latch 32 is positioned so that under these conditions it will be engaged by the hook of hooked portion 30.

Application of a force directly to member 20, however, causes projection 26 to engage key lever 12, so that key lever 12 and member 20 are moved as a unit. Pin 44, inthis case, is revolved around the axis of pin 48. Conversely, if pin 44 is revolved around the axis of pin 48 by a force applied thereto by bar 53 in response to a force being applied to tab 64 or the actuation of solenoid armature 58, member 20 and key lever 12 again will be moved as a unit in a similar manner. However, in these latter two cases, there will be no relative rotation between member 20 and key lever 12. Therefore, hooked portion 30 will not be rotated forward to engage latch 32.

' Member 20, strip 36 and solenoid armature 40 may be easily disassembled from the rest of the typewriter by the simple expedient of removing only screw 22.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

I claim:

1. In a typewriter having a shift apparatus, the combination comprising a shift key lever adapted to be pivotally mounted on said typewriter at a first point and to operate said shift apparatus, said key lever having a free end, a member lying in a plane parallel to the length of said key lever, fastening means for pivotally mounting said member on said key lever at a second point thereon located intermediate said first point and said free end for rotation relative to said key lever about an axis perpendicular to said plane, a stop projection integral with said member and extending perpendicular thereto to overlap said key lever at a third point intermediate said second point and the free end thereof and thereby prevent relative rotation of said member with respect to said key lever in one direction, movable means linked between a fourth point fixed relative to said typewriter and a fifth point located on said member a given distance from said second point for allowing translational motion of said fifth point relative to said typewriter only in response to a first force which urges rotation of said member about said second point in said one direction being applied to said member, whereby the application only to said key lever of a second force which rotates the free end thereof in said one direction relative to said typewriter causes translational motion of said second point relative to said typewriter and rotation of said member about said second point in a direction opposite to said one direction, said member having a hook depending therefrom, and a latch secured to a sixth point fixed to said typewriter, said latch being positioned to be engaged by said hook only in response to said second force being applied to said key lever.

2. The combination defined in claim 1, wherein said member has a slot therein located at said fifth point, and wherein said movable means comprises a second member secured to said fourth point for rotation about an axis perpendicular to said plane, and a pin extending from said second member, said pin being parallel to the axis of rotation of said second member and located at a given distance therefrom in cooperative relationship with respect to said slot, said pin being inserted through said slot, and said slot being shaped to permit said pin to revolve about the axis of rotation of said second member in response to said first force being applied to said firstmentioned member.

3. The combination defined in claim 2, further comprising a shift button attached to said first-mentioned member to which said first force may be applied.

4. The combination defined in claim 2, further comprising a shift-lock button attached to said key lever to which said second force may be applied.

5. The combination defined in claim 1, wherein said member includes a first flat strip lying in said plane and extending beyond said key lever in a direction substantially perpendicular to the length of said key lever, and

said combination further comprises a second flat strip lying in a second plane parallel to said first-mentioned plane and which is located on the opposite side of said key lever from said member, said second strip being fixedly attached to said key lever and extending adjacent and parallel to said first fiat strip, said second fiat strip having a hole therein near one end thereof, a third fiat strip having a pin projecting perpendicular thereto near one end thereof, said third strip lying between said first and second strips with said pin detachably inserted in the hole of said second strip, and an armature of a solenoid having one end of said armature attached to the other end of said third strip, said armature being cooperatively positioned relative to said solenoid so as to be moved by a magnetic force in response to said solenoid being energized, said magnetic force being in a direction to rotate said key lever in said one direction through the linkage provided by said second and third strips, whereby said magnetic force acts as said second force.

6. The combination defined in claim 5, wherein said fastening means are detachable.

7. The combination defined in claim 6, wherein said member has a slot therein located at said fifth point, and wherein said movable means comprises a second member secured to said fourth point for rotation about an axis perpendicular to said first-mentioned plane, and a second pin extending from said second member, said second pin being parallel to the axis of rotation of said second member and located a given distance therefrom in cooperative relationship with respect to said slot, said second pin being inserted through said slot, and said slot being shaped to permit said second pin to revolve about the axis of rotation of said second member in response to said first force being applied to said first-mentioned member.

8. The combination defined in claim 7, wherein said hook is located at the end of said first strip.

9. The combination defined in claim 8, wherein said second strip includes a shift-lock button at the end thereof remote from said one end thereof to which said second force may be applied.

10. The combination defined in claim 9, further comprising a shift button attached to said first-mentioned member to which said first force may be applied.

11. In a typewriter having a shift apparatus, the combination comprising a shift keylever adapted to be pivotally mounted on said typewriter at a first point and to operate said shift apparatus, said shift key lever having a free end, a member lying alongside a portion of the length of said key lever, means pivotally mounting said member on said key lever at a second point thereon located intermediate said first point and said free end for pivotal movement relative to said key lever about an axis transverse thereto, a stop on said member and extending transversely thereto to overlap said key lever at a third point intermediate said second point and the free end thereof and thereby prevent pivotal movement of said member with respect to said key lever in one direction, means linked to said typewriter and adapted to occupy either one position or a second position relative thereto, said means being linked to a portion of said member for allowing translational motion of said portion relative to said typewriter only in response to a first force which urges pivotal movement of said member about said second point in said one direction being applied to said member, whereby the application only to said key lever of a second force which moves the free end thereof in said one direction relative to said typewriter causes translational motion of said second point relative to said typewriter and pivoting of said member about said second point in a direction opposite to said one direction, said member having a hook, and a latch fixed to said typewriter, said latch being positioned to be engaged by said hook only in response to said second force being applied to said key lever.

12. A shift latch and release mechanism for typewriters comprising a shift lever operable from a normal elevated position to a depressed position, a latch member having a latching surface under said shift lever, a shift lock lever pivoted to said shift lever at a point above the latching surface of said latch member, a latch surface on said shift lock lever extending in proximity to said latching surface, and a fulcrum for said shift lock lever at the rear of its pivot whereby depression of said shift lever will cause said shift lock lever to rock about said fulcrum and projectthe latch surface thereof into engagement with the latching surface of said latch member.

13. A shift latch and release mechanism for typewriters comprising a shift lever operable from a normal elevated position to a depressed position, a latch member having a latching surface under said shift lever, a shift lock lever pivoted to said shift lever at a point above the latching surface of said latch member, a latch surface on said shift lock lever extending in proximity to said latching surface, a fulcrum for said shift lock lever at the rear of its pivot whereby depression of said shift lever will cause said shift lock lever to rock about said fulcrum and project the latch surface thereof into engagement with the latching surface of said latch member, and a shift lock release key carried by said shift lock lever whereby the shift lock lever may be rotated about its pivot to disengage said latch and latching surfaces.

14. A shift latch and release mechanism for typewriters comprising a shift lever operable from a normal elevated position to a depressed position, a latch member having a latching surface under said shift lever, a shift lock lever pivoted to said shift lever at a point above the latching surface of said latch member, a latch surface on said shift lock lever extending in proximity to said latching surface, a fulcrum connected to said shift lock lever at the rear of its pivot whereby depression of said shift lever will cause said shift lock lever to rock about said fulcrum and project the latch surface thereof into engagement with the latching surface of said latch member, a depressible shift release lever remote from said shift lever, and a connection between said shift release lever and said fulcrum whereby depression of said shift release lever will, through said fulcrum, rotate said shift lock lever about its pivot to disengage said latch and latching surfaces.

15. A shift latch and release mechanism for typewriters comprising a shift lever operable from a normal elevated position to a depressed position, a latch member having a latching surface under said shift lever, a shift lock lever pivoted to said shift lever at a point above the latching surface of said latch member, a latch surface on said shift lock lever extending in proximity to said latching surface, a fulcrum connected to said shift lock lever at the rear of its pivot whereby depression of said shift lever will cause said shift lock lever to rock about said fulcrum and project the latch surface thereof into engagement with the latching surface of said latch member, a shift lock release key carried by said shift lock lever, a depressible release lever remote from said shift lever, and a connection between said shift release lever and said fulcrum whereby depression of either said shift lock release key or said shift release lever will rotate said shift lock lever about its pivot to disengage said latch and latching surfaces.

References Cited in the file of this patent UNITED STATES PATENTS 2,388,351 Tholztrup Nov. 6, 1945 

